Electric switch



March 19 1940. T. F. JOHNSON ELECTRIC SWITCH Filed April 19, 1938 3 Sheets-Sheet 1 March 19, 1940. T. F. JQHNSON ELECTRIC SWITCH Fileci April 19, 1958 3 Sheets-Sheet 2 JN V 1 (:1 Momm March 19, 1940. T, JQHNSON 2,194,021

ELECTRIC SWITCH Filed April 19. 1958 5 Sheets-Sheet 3 /0 wuc-n for,

Patented Mar. 19, 1940 UNITED STATES ELECTRIO' SWITCH Tomlinson F. Johnson, Atlanta, Ga.

Application April 19, 1938, Serial No. 202,950

.. 13 Claims.

This invention relates to electric switches and aims, among other objects, to provide a novel high tension electric switch of the type having a ventilated blade and provided with novel operating means to retract and advance the blade axially and swing it to open and closed positions. Another aim is to provide a relatively simple, inexpensive and rugged switch structure of this type which permits maximum contact pressure between the jaw and the blade and larger contacts to be used.

Other aims and advantages of the invention will appear in the specification, when considered in connection with the accompanying drawings, wherein:

Fig. 1 is a side elevation of a single phase switch embodying the invention;

Fig. 2 is a top plan view of the switch shown in Fig. 1;

Fig. 3 is a similar top plan view showing the switch blade retracted;

Fig. 4 is a fragmentary sectional view taken on an enlarged scale on the line 44 of Fig. 2;

Fig. 5 is a sectional view taken on the line 5-5 of Fig. 4;

Fig. 6 is a fragmentary sectional view similar to Fig. 4 showing the parts in a different position; and

Fig. 7 is an enlarged sectional view taken on the line 1-1 of. Fig. 1.

Referring particularly to the drawings, the single phase switch there shown is mounted on a channel support I0 and two stationary insulators II and I2. It is adapted to be operated by a third insulator l3 which is mounted for rotation relative to the supporting channel, carrying a stub shaft H at the top and an operating crank arm l5. It will be understood that switches of this type are mounted in gangs, three such units being employed in a three phase system and adapted to be operated manually by well known mechanism (not shown).

The insulator H is shown as having a bracket It to which a pair of horizontal spring plates l'l are connected. These spring plates are split at their forward ends and carry pairs of opposed jaws or contacts |8, the arrangement being such that the jaws present a maximum contact area and each jaw part is free to adjust itself upon and engage the switch blade. The bracket also carries the usual upstanding arcing horn IS'and a line connecting lug or bracket 20.

The switch is shown as having a saddle shaped bracket 2| pivoted to a pair of arms 22 on a cap plate 23 of the insulator l2 and carrying a pipe blade 24 with a flattened c ontact end 25 best shown in Figs. 2 and 3. The forward end portion of. the blade also carries an arcing horn 26 secured to a clamping collar 21. The rear end of the switch blade isshown as being connected for parallel swinging movement relative to the bracket 2| by means of pairs of parallel links 23 pivoted at their lower ends to ears 29 on the bracket and at their upper ends to a saddle block 30 secured by bolts 3| to the switch blade. The arrangement is such that when the parallel links are swung to their forward position as shown in Figs. 1, 2 and 4, the blade 24 is advanced to its closed position and, when they are swung rearwardly as shown in Figs. 3 and 6, the blade is retracted from the jaw. At the contact end, this movement is substantially axial. When the blade is retracted, it is free to swing to its open position.

The cap member on the stationary insulator |2 has pairs of rearwardly extending arms 32, to the'rearward ends of which brace bars 33 in the form of copper conductors are connected and extend to the top of therotatable insulator I3 90 and their rear ends are secured to forwardly extending arms 34 connected to an upper bearing member 35 around the stub shaft H on said insulator. The member 35 has a line connecting lug 36 which is electrically connected to the rear end of the switch blade by a braided conductor 31 connecting the saddle block 30 to one of the bars 33.

To operate the switch blade an arm or crank 33 is secured to the stub shaft 14 and carries a double jointed link 39 which is pivotally connected at its forward end to upstanding ears 40 on the saddle block 30. The arrangement is such that when the crank arm 38 is turned clockwise as viewed in Figs. 2 and 3, it will exert a horizontal pull on the switch blade and swing it rearwardly on the two pairs of links 28 until the rear end of the blade again rests in the saddle bracket as shown in Fig. 6, with the blade tip fully withdrawn from the jaw, as shown in Fig. 3.

To hold the switch blade and its bracket in its horizontal position while the blade is being retracted or advanced as well as while in closed position, there is shown a pair of opposed upstanding arms 4| rigidly connected relative to the saddle bracket 2| by means of bolts 42 carrying bushings 43 on which the parallel links 28 are pivoted. A crank arm 44 above the operating crank 38 is mounted for relative rotation on the stub shaft l4 and a second double jointed link 45 carried by the same arm is pivotally connected at its forward end, to a cross bar 46 pivotally mounted between the upper ends of the upstanding arms 4 I. The link 45 and its arm 44 not only act as a limiting stop to hold the switch blade and its saddle bracket 2| horizontal but also as a stiff leg to prevent the operating link 39 from breaking the pivoted joint or tending to. swing the blade vertically until it is fully retracted. This arrangement permits the full power applied to the operating arm 38 to be transmitted to the switch blade either to retract or advance it and this is quite advantageous in cold climates when ice accumulates on the switch jaws. However, it is to be understood that the switch jaws may be and usually are covered with ordinary sleet hoods.

Referring to Figs. 1, 3 and 4, the operating arm 88 is shown as having a strap metal finger 41 secured to it intermediate its ends and extending laterally in a counterclockwise direction, as viewed in Figs. 2 and 3. It has an upstanding bent end 45 to engage one side of the freely rotatable arm 44 and break the stiff leg joint just before the operating arm 38 reaches its blade opening position, the purpose being to permit the continued movement of the operating arm 38 to impart vertical swinging movement to the switch blade and its connected parts. The horizontal pivots of the double joints in the operating links permit this swinging movement, the parts being shown in their fully operated positions by dotted lines in Fig. 4. It will be observed that the rear end of the switch blade remains in its retracted position within the saddle bracket when it is in its fully opened position because the pivoted connecting members at the forward ends of the two links 39 and 45 are closely adjacent to each other and any tendency of the link 39 to pull the blade out of its saddle is resisted by the upper link joint. Also, the weight of the blade 24 tends to hold it in its retracted saddle engaging position by gravity. It will remain in this seated position due to gravity until it swings to the horizontal position (Fig. 6).

To close the switch, it will be understood that the insulator I3 is turned in a counterclockwise direction as viewed in Figs. 2 and 3 and, after the blade swings to its horizontal position, the link 38 imparts forward axial movement to the blade and the operating parts, straightening out the link 45 to its stiff leg position (shown in Figs. 2 and 4), when said link locks the blade closed. During the final movement of the operating arm 38, the parallel links 28 swing to their forward positions as shown in Figs. 1, 2 and 4. It will be observed that when the blade and the saddle bracket are in the horizontal position, the mechanical advantage of the operating arm is increased because the effective lever arm is decreased. This is a very decided advantage because it enables the operating arm to exert a powerful closing thrust on the blade so that spring jaws with large contact areas may be employed.

Referring to Fig. '7, the crank arm H for operating the rotatable insulator i3 is shown as having radial lugs or cars 49 carrying adjustable stop members in the form of set screws 50 cooperating with stationary abutments 5| secured to the supporting channel Hi. It will be understood that these stop members are so adjusted as to limit the rotation of the insulator and operating arm 38. This arrangement makes it impossible for an attendant to operate the switch in the wrong direction.

From the foregoing description, it will be seen that the improved switch is very simple and rugged in its construction and efiective in its operation. It is well adapted for use on high tension transmission systems in all climates. There are no delicate parts which require frequent adjustment, replacement or repairs. It may be manufactured and installed at a relatively low cost. In fact, such switches are eminently adapted for use on all high tension systems.

Obviously, the present invention is not restricted to the particular embodiment thereof herein shown and described. Moreover, it is not indispensable that all the features of the invention be used conjointly, since they may be employed advantageously in various combinations and sub-combinations.

What is claimed is:

1. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable operating insulator having blade actuating means connected to impart said movements to the blade; and a jointed stifl leg also connected to the rotatable insulator and associated with the blade normally to maintain the blade in switch closing position and to prevent swinging movement of the blade until it is retracted.

2. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable insulator mounted adjacent to said blade supporting insulator; a crank arm and double jointed operating link connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto; and a double jointed stiff leg also carried by the rotatable insulator and connected to limit the swinging movement of the blade and preventing the operating link from swinging the blade before it is retracted from the jaw.

3. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable insulator mounted adjacent to said blade supporting insulator; a crank arm and double jointed operating link connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto; a second arm freely rotatable with respect to said rotatable insulator; a double jointed stifl leg link connected to limit the swinging movement of the blade toward closed position and permitting axial movement only to be imparted to the blade; and means on the operating arm to break the stiff leg link and thereby permit opening swinging movement to be imparted by the operating link to the blade after it is retracted.

4. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable insulator mounted adjacent to said blade supporting insulator; a crank arm and double jointed operating link connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto; and means also carried by said rotatable insulator to limit the closing swinging movement of the blade and hold it in position to register with the jaw so that axial closing and retracting movements only may be imparted to the blade while it is so held.

5. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable insulator mounted adjacent to said blade supporting insulater; a crank arm and double jointed operating link connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto; a. double jointed stiii leg member also carried by the rotatable insulator and connected to prevent the blade from swinging while the operating link is retracting it; and means asssociated with the crank connected to break the stifi leg and permit the operating link to impart swinging movement to the blade after it is retracted.

6. In an electric switch of the character described, a pair of' spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable operating insulator having blade actuating means connected to impart said movements to the blade; and means also carried by said rotatable insulator to support and limit the closing swinging movement oi the blade and hold it in position to register with the jaw so that axial closing and retracting movements may be imparted to the blade while it'is so held.

7. In an electric switch of the character'described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable operating insulator having blade actuating means connected to impart said movements to the blade; an arm ireely rotatable with respect to said rotatable insulator; a doublejointed stiff leg link con nected to limit the swinging movement of the blade toward closed position and permitting axial movement only to be imparted to the blade; and

means on the operating arm to break the stifl leg link and thereby permit opening swinging movement to be imparted by the operating link to the blade after it is retracted.

8. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable operating insulator having blade actuating means connected to impart said movements to the blade; a double jointed stifl. leg member also carried by the rotatable insulator and connected to prevent the blade from swinging while the operating link is retracting it; and means connected to break the stiff leg during the final retracting movement of the blade and permitting the operating link to impart swinging movement to the blade after it is retracted.

9. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one oi said insulators; a blade support pivotally connected to the other insulator; pairs 01 parallel pivoted links on the support; a blade connected to said links so that it.

is capable of both axial and swinging movement; an operating insulator having actuating means connected to said blade; and a stiff leg carried by said operating insulator and connected to said pivoted support causing said actuating means to impart retracting movement only to the blade when it is closed.

10. In an electric switch oi the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; a blade support pivotally connected to the other insulator; pairs of parallel pivoted links on the-support; a blade connected to said links and normally resting on said support; a rotatable in- ,sulator mounted behind the blade supporting insulator; a crank arm and double jointed operating link connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto; and a double jointed stifi leg parallel with said operating link connected to limit the swingingmovement of the blade and preventing the operating link from swinging the blade beiorei t is retracted from the jaw.

11. In an electric switch of thecharacter described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; a blade support pivotally. connected to said second insulator; pairs of parallel pivoted links on the support; a blade connected to said links to permit both axial and swinging movement of the blade; a rotatable insulator mounted adjacent to the blade supporting insulator; a crank arm and double jointed operating link connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto; a second arm freely rotatable with respect to said rotatable insulator; a double jointed stifl leg link parallel with the operating link connected to limit the swinging movement of the blade toward closed position and permitting axial movement only to be imparted to the blade; and means on the operating arm to break the stifl leg link and thereby permit opening swinging movement to be imparted by the operating link to the blade after it is retracted.

12. In an electric switch of the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; an axially retractable and swinging blade mounted on the other insulator; a rotatable operating insulator having blade actuating means connected to impart said movements to the blade; at stifl. leg connected between the rotatable insulator and the blade to prevent swinging movement 0! the blade until it is retracted; and adjustable stop means to limit both the opening and closing movements of said operating insulator.

13. In an electric switch oi the character described, a pair of spaced supporting insulators; a jaw mounted on one of said insulators; a blade support pivotally connected to said second insulator; pairs of parallel pivoted links on the support; a blade connected to said links to permit both axial and swinging movement of the blade; a rotatable insulator mounted adjacent to the blade supporting insulator; a crankarm and double jointed operating link connecting said rotatable insulator to the blade to impart both retracting and swinging movement thereto; a second arm ireely rotatable with respect to said rotatable insulator; a double jointed stifl leg link connected to limit the swinging movement of the blade toward closed position and'permitting axial movement only to be imparted to the blade; means on the operating arm to break the stifl leg link and thereby permit opening swinging movement to be imparted by the operating link to the blade after it is retracted; and stop means to limit the operating movement of said rotatable insulator.

TOMHNSON F. JOHNSON. 

